Integrated circuits (ICs) are used in various applications and devices. ICs in some devices can be configured to store user and configuration data in a memory module. The memory module may be an embedded non-volatile memory (NVM) module that has the capability to retain the stored data even when the device is not powered. However, when the device is used in security-sensitive systems, secured data stored in the NVM module may be accessible to unauthorized individuals.
If the stored data can be read from the system, the data can be stored and used in another similar device. For instance, sensitive data within the system can be retrieved and duplicated in another similar system. Generally, ICs in programmable devices do not have the capability to put the device in a “self-destruction” mode that will automatically erase all user or configuration data stored when the IC detects unauthorized attempts to access the device.
Such devices may be exposed to unwanted access by unauthorized third parties. To prevent this, an IC with a built-in security mechanism is needed. In some systems, there is generally a security feature that will prevent data from being read or transferred through any access port, e.g., through a Joint Test Action Group (JTAG) scan chain. This generally prevents access to configuration data stored within the device. However, in most cases, sensitive user data stored in the NVM within the device may still be accessible through the JTAG interface.
Therefore, in order to ensure that security-sensitive data is protected from unauthorized or unwanted access, it is desirable to have a built-in self-destruction mechanism in such systems. ICs in such systems should be able to perform a self-destruct operation when necessary. The self-destruct operation may erase both the user and configuration data or any other sensitive data that are stored within the system. Such an operation would ensure that the system would be disabled and any sensitive data stored within the system would be erased. It is within this context that the invention arises.